The diffusion of technological knowledge through interlaced networks

In the last decade, many papers discussed the basic features of the networks formed by knowledge diffusion. In this paper, we show that a network formed by the spreading of technological information, represented by the patents citation network, does not obey the expected power law behavior and, therefore, is not a scale-free network. We mapped a network formed by almost 600 000 patents, covering a 40 years period. Although the complete network is not scale-free, small portions within the whole network can be described by power laws. The network combines several fields of knowledge, but those power law portions belong to specific fields of technological knowledge. A mathematical model is introduced, which can explain the basic dynamics of the formation of this network.